Methionine-functionalized chitosan–Pd(0) complex: A novel magnetically separable catalyst for Heck reaction of aryl iodides and aryl bromides at room temperature in water as only solvent

Article abstract of DOI:10.1002/aoc.3638

We report a novel catalyst system with an immobilized palladium metal-containing magnetic nanoparticle core (ImmPd(0)-MNPs) for the Heck reaction. ImmPd(0)-MNPs was found to be an exceptionally mild and versatile catalyst for the Heck reaction of aryl iodides and bromides at room temperature. The catalyst was simply recovered using an external magnet from the reaction mixture and recycled six times. The results showed that the catalyst was very active and stable. Moreover, the reaction was carried out in water as a green and environmentally acceptable solvent. In terms of scope and mildness, ImmPd(0)-MNPs is an improvement over previously reported catalysts for Heck coupling methods.

Full text of DOI:10.1002/aoc.3638

Received: 30 July 2016
DOI 10.1002/aoc.3638
Accepted: 24 August 2016
F U L L PA P E R
Methionine‐functionalized chitosan–Pd(0) complex: A novel
magnetically separable catalyst for Heck reaction of aryl iodides
and aryl bromides at room temperature in water as only solvent
Abdol R. Hajipour1,2 | Zeinab Tavangar‐Rizi1
1 Pharmaceutical Research Laboratory, Department
We report a novel catalyst system with an immobilized palladium metal‐containing
magnetic nanoparticle core (ImmPd(0)‐MNPs) for the Heck reaction. ImmPd(0)‐
MNPs was found to be an exceptionally mild and versatile catalyst for the Heck
reaction of aryl iodides and bromides at room temperature. The catalyst was simply
recovered using an external magnet from the reaction mixture and recycled six times.
The results showed that the catalyst was very active and stable. Moreover, the
of Chemistry, Isfahan University of Technology,
Isfahan 84156, Iran
2 Department of Pharmacology, University of
Wisconsin, Medical School, 1300 University
Avenue, Madison, Wisconsin 53706‐1532, U.S.A.
Correspondence
Abdol R. Hajipour, Pharmaceutical Research
Laboratory, Department of Chemistry, Isfahan
University of Technology, Isfahan 84156, Iran.
Email: haji@cc.iut.ac.ir
reaction was carried out in water as a green and environmentally acceptable solvent.
In terms of scope and mildness, ImmPd(0)‐MNPs is an improvement over previously
reported catalysts for Heck coupling methods.
Funding Information
Center of Excellence in Sensor, and Green
Chemistry Research (IUT), IR Iran (A.R.H.),
Isfahan University of Technology (IUT)
KEYWORDS
Heck reaction, ImmPd(0)‐MNPs, room temperature, water
1
|
INTRODUCTION
used as appropriate support materials to develop highly effi-
cient recycling methods for catalysts. They possess some
One of the most challenging tasks in organic chemistry is to
design convenient routes for cross‐coupling reactions includ-
ing reusable, efficient and green catalysts.[1] With the final
goal of solving environmental problems, the use of water
and its co‐solvents as the reaction media instead of toxic
organic solvents has gained high importance in the field of
catalysis.[2] In the context of green chemistry, a convenient
route for cross‐coupling reactions involves reusable palla-
dium nanoparticles that promote these reactions in green
solvents.[3–5] Homogeneous palladium catalysts used in these
reactions have several drawbacks such as time‐consuming
work‐up procedures attendant with inefficient recycling. A
heterogeneous palladium catalyst can solve these prob-
lems.[6–13] Metal nanoparticles have become attractive tools
for catalysis because of their high surface area‐to‐volume
ratio. A key challenge in the application of these catalysts is
accumulation of nanoparticles, which may lead to deactiva-
tion.[14,15] Furthermore, isolation and recovery of heteroge-
neous catalysts from a reaction mixture become difficult as
their size decreases to the nanoscale. Thus, magnetic
nanoparticles (MNPs) which have emerged as bridges
between homogeneous and heterogeneous catalysts can be
advantages which make them more sustainable, such as easy
separation using an external magnet, high reactivity, very
high surface area‐to‐volume ratio, and high thermal and
mechanical stability. Because of these advantages, recent
advances have led to the use of magnetically recoverable
catalysts in coupling reactions.[16–18] Development of MNP‐
supported catalysts depends on two features: primarily, the
synthesis of size‐controlled and mono‐dispersed MNPs;[17,19]
secondly, avoiding the aggregation of MNPs through their
surface stabilization. Thus, using an appropriate surface
modification for MNPs can help to achieve stability and
well‐dispersed active species.
In recent years, a variety of polymeric support materials
have been used as catalyst carriers in chemical reactions.[20–22]
As one kind of widely used biopolymers, chitosan which has
two types of reactive functional groups, amino groups and
hydroxyl groups,[23] has been used as a suitable solid support
for the immobilization of a metal catalyst.[24] The main
disadvantages of chitosan, which significantly limit its use
as an effective and recyclable biopolymer, are poor chemical
resistance and mechanical strength. Accordingly, it is often
necessary to use a stronger ligand to help bind the metals more
Appl Organometal Chem 2016; 1–7
wileyonlinelibrary.com/journal/aoc
Copyright © 2016 John Wiley & Sons, Ltd.
1

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HAJIPOUR AND TAVANGAR‐RIZI
strongly for catalytic applications. From the point of view of
biodegradability, implanting of amino acids[25–27] to chitosan
via carbodiimide coupling protocols would result in amphi-
philic derivatives, which improve the formation of nanoscale
micellar structures in aqueous environments. Previously, we
reported proline‐functionalized chitosan–palladium(II) as an
efficient catalyst for the Suzuki reaction.[28]
magnetic support in ethanol to afford ImmPd(0)‐MNPs as
the final catalyst.
The following methods were used to characterize the
catalyst: transmission electron microscopy (TEM); field‐
emission scanning electron microscopy (FE‐SEM); powder
X‐ray diffraction (XRD); and energy‐dispersive X‐ray
spectroscopy (EDX). Fourier transform infrared (FT‐IR)
spectroscopy was used for characterizing CS–methionine
and Fe3O4–CS–methionine. Thermal behavior of the catalyst
was also studied using thermogravimetric analysis. The
magnetization curve of ImmPd(0)‐MNPs indicates the
magnetic behavior of the catalyst.
The TEM image of the ImmPd(0)‐MNPs catalyst
(Figure 1) shows that the Pd nanoparticles with near spherical
morphology are accumulated onto the magnetic functional-
ized chitosan with relatively good monodispersity. The
histogram indicating the size distribution of Pd nanoparticles
is also shown in Figure 1, constructed according to the data
acquired from the TEM image, showing an average size of
6–7 nm. The FE‐SEM images in Figure 2 show spherical
external morphologies of the catalyst. Also, to determine
the Pd content on the catalyst, the catalyst was reacted with
concentrated HCl to digest the Pd particles and then analyzed
Palladium‐catalyzed Heck cross‐coupling reactions[29]
are some of the most common and practical methods for the
construction of new carbon–carbon bonds and are widely
used in industrial and academic applications for the synthesis
of a large variety of organic substances, bioactive compounds
and natural products. Previous studies of Heck arylation were
done using harsh conditions such as organic solvents,[30] high
temperature,[1] organic bases[31] and long reaction time
(or less efficiency for bromobenzene derivatives).[32] Further-
more, reports of Heck arylation at room temperature are
rare,[33] so it is highly desirable to design an active and stable
catalyst for the reaction in water at room temperature.
Accordingly, in the work reported in this article, we
introduced palladium nanoparticles immobilized on magnetic
methionine‐functionalized chitosan in order to develop a new
and highly efficient heterogeneous catalyst for used under
green reaction conditions and we evaluated its application
in Heck reactions of aryl iodides and aryl bromides in water
at room temperature.
2
| RESULTS AND DISCUSSION
2.1 | Preparation and characterization of palladium
nanoparticles immobilized on Fe3O4–Chitosan (CS)–
methionine (ImmPd(0)‐MNPs)
As shown in Scheme 1, the route to prepare the catalyst
contains three steps. First, CS–methionine was prepared by
the reaction between methyl methioninate and chitosan in
dimethylformamide (DMF). In the second step, CS–
methionine was treated with Fe3O4 nanoparticles prepared
by mixing of FeCl3⋅6H2O and FeSO4 according to a reported
procedure,[34] to obtain Fe3O4–CS–methionine as a magnetic
substrate. Finally, palladium acetate was grafted into this
FIGURE 1 (a) TEM image of ImmPd(0)‐MNPs catalyst showing the mor-
phology of Pd nanoparticles on the magnetic chitosan support. Beneath is
the histogram of the particle size distribution. (b) TEM image of ImmPd
(0)‐MNPs catalyst after eight recycles
SCHEME 1 Synthetic paths for the preparation of ImmPd‐MNPs catalyst
FIGURE 2 FE‐SEM images of ImmPd(0)‐MNPs catalyst complex

HAJIPOUR AND TAVANGAR‐RIZI
3
using the inductively coupled plasma (ICP) technique. The
amount of palladium is found to be 7.1 ppm (7.1 mg l−1).
The XRD study of ImmPd(0)‐MNPs confirms the pres-
ence of highly dispersed palladium complexes in the structure
of the modified chitosan support. According to Figure 3, a
sharp peak at 2θ = 40°, which is related to palladium,
indicates the crystalline nature of the palladium species.
The peaks which are indexed as (111), (200), (220), (311)
and (222) indicate the cubic phase of palladium nanoparticles
(JCPDS 01–087‐0638). As presented in Figure 3, 11
characteristic diffraction peaks (2θ = 30.1° (220), 35.5°
(311), 43.1° (400), 47.2° (331), 53.5° (422), 57.0° (511),
62.6° (440), 75.1° (622), 82.0° (551), 86.8° (642) and 89.8°
(731)) can be clearly observed for Fe3O4 particles, which
are associated with the cubic phase of Fe3O4 (JCPDS
01–075‐0033).
Comparison among the FT‐IR spectra (Figure 5) of
pure chitosan, CS–methionine, Fe3O4 and the Fe3O4–
CS–methionine substrate indicates that some absorption
bands in the spectrum of Fe3O4–CS–methionine are present
in those of both chitosan and Fe3O4. The FT‐IR spectrum of
CS–methionine reveals a carbonyl group absorption band,
which confirms that methionine has been attached into the
chitosan after the reaction between chitosan and methioninate.
A typical strong and broad band appears at around 3419 cm−1
,
related to the stretching vibration of the ─OH group, the
extension vibration of the N─H group and inter‐hydrogen
bonds of polysaccharide in the Fe3O4–CS–methionine
spectrum.[35,36] In addition, the intensity of the band at
1385 cm−1 is increased in the spectrum of the CS–methionine
material; this is associated with the introduction of additional
amine groups.[35] Bands at 3419, 2925, 2354, 1632, 1394,
1064 and 566 cm−1 correspond to the bonds in Fe3O4–CS–-
methionine. The band at 566 cm−1 is assigned to the Fe─O
stretching vibration of Fe3O4.[37] In the FT‐IR spectrum of
As clearly observed, according to the EDX spectrum
(Figure 4), the presence of palladium is demonstrated on
the magnetic chitosan in the ImmPd(0)‐MNPs catalyst. The
EDX spectrum also indicates other elements, including S, O
and Fe, which are present in the Fe3O4–CS–methionine
substrate.
CS–methionine, an additional band appears at 1655 cm−1
;
this band is representative of the (─CON─) carboxyl amide
group vibration of the methionine moiety.
TGA was used to investigate the thermal stability of the
catalyst (Figure 6). The weight loss for all samples occurring
up to 200°C is ascribed to the loss of physically adsorbed
solvent molecules and moisture.[30] The mass loss above
200°C in the TGA curve of the magnetic catalyst is related
to the decomposition of polysaccharide chain. So, the
elevated temperature for chitosan decomposition indicates
the high thermal stability of the catalyst.
The magnetization curves of ImmPd(0)‐MNPs and Fe3O4
indicate the magnetic behavior of ImmPd(0)‐MNPs
(Figure 7). The two samples demonstrate zero coercivity
and remanence on the magnetization curve. The lack of a hys-
teresis loop denotes the magnetic property and the tendency
of the catalyst to be able to be separated efficiently from the
FIGURE 3 XRD pattern of ImmPd(0)‐MNPs catalyst
FIGURE 5 FT‐IR spectra of pure chitosan, CS–methionine, Fe3O4 and
Fe3O4–CS–methionine substrate
FIGURE 4 EDX spectrum of ImmPd(0)‐MNPs catalyst

4
HAJIPOUR AND TAVANGAR‐RIZI
their bond formation via their hydroxyl functional groups.
Even with this reduction in the saturation magnetization, the
catalyst still can be separated simply from solution using an
external magnet.
2.2 | Heck reaction catalyzed by ImmPd(0)‐MNPs
After characterizing the prepared catalyst, we explored the
catalytic properties of ImmPd(0)‐MNPs for C─C bond for-
mation via a Heck coupling reaction. In our initial study,
we chose the reaction between 4‐iodotoluene and methyl
acrylate as a model reaction to compare the effects of various
conditions such as solvent, base, temperature and quantity of
catalyst. The optimization of conditions is summarized in
Table 1.
FIGURE 6 Typical TGA curve of ImmPd(0)‐MNPs catalyst
Initially, we chose water–ethanol (1:1) and K2CO3 as the
media for the Heck reaction of 4‐iodotoluene with methyl
acrylate under reflux conditions. The reaction proceeds
completely after 50 min with a 94% GC yield (Table 1,
entry 1). Since our objective was an exceedingly versatile
catalyst for room temperature Heck couplings of aryl halides,
we were encouraged to observe the ImmPd(0)‐MNPs catalyst
as significantly active, which permits the room temperature
coupling of 4‐iodotoluene with methyl acrylate (Table 1,
entry 2). Results obtained for other conditions also reveal that
the catalyst is highly efficient for Heck coupling. When water
is used as the solvent, the product yield does not reduce
(Table 1, entry 3) and because of this, water was chosen for
this reaction as a green medium. Heck couplings between
lipophilic aryl iodides and acrylates, using K2CO3 as base
and water as solvent, could more successfully be carried out
FIGURE 7 Magnetization curves of ImmPd(0)‐MNPs catalyst and Fe3O4
using
a
phase transfer agent. As expected, when
reaction mixture using an external magnetic field. Further,
the reduction in the magnetization value of the catalyst in
comparison with Fe3O4 indicates that the surface of Fe3O4
is covered by the attachment of chitosan molecules through
tetrabutylammonium bromide (TBAB) is added to the reac-
tion mixture as an additive, the reaction time is reduced from
5.5 h to 1:5 h to achieve a high yield (Table 1, entry 4). The
influence of base on the reaction was also investigated
TABLE 1 ImmPd(0)‐MNPs‐catalyzed Heck reaction between 4‐iodotoluene and methyl acrylatea
Entry
Solvent
Base
Temp.
Time (h)
Yield (%)b
1
H2O–ethanol (1:1)
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K3PO4
KOH
Reflux
r.t.
0.8
2
94
70
90
96
96
90
94
2
H2O–ethanol (1:1)
3
H2O
H2O
H2O
H2O
H2O
r.t.
5.5
1.5
1.5
2
4c
5d
6c
7c
r.t.
r.t.
r.t.
r.t.
1.5
aReaction conditions: 4‐iodotoluene (0.5 mmol), methyl acrylate (0.6 mmol), base (1 mmol), catalyst (0.025 g, 0.34 mol%) and solvent (2 ml).
bGC yield.
cTBAB (0.5 equiv.) was added as an additive.
dReaction conditions: 4‐iodotoluene (0.5 mmol), methyl acrylate (0.6 mmol), base (1 mmol), catalyst (0.015 g, 0.21 mol%), TBAB (0.5 equiv.) and solvent (2 ml).

HAJIPOUR AND TAVANGAR‐RIZI
5
(Table 1, entries 6 and 7). It is evident from Table 1 that
different bases show similar effects. Since K2CO3 is cheap,
acceptable and one of the commonly used bases for the Heck
reaction, we decided to use it as the base for the reaction. The
model reaction proceeds efficiently when the catalyst loading
decreases from 0.025 g (0.34 mol%) to 0.015 g (0.21 mol%)
(Table 1, entry 5).
selectively react with olefin in the presence of aryl chlorides
(Table 2, entry 11).
Compared with previous literature on the Heck coupling
reaction, the marked features of our method are:
• the reaction system is simple;
• removal of toxic reagents and homogeneous catalysts;
• the yields of the products are high;
• water is used as a green medium;
2.3 | Heck reaction of various substrates catalyzed by
ImmPd(0)‐MNPs
• the ImmPd‐MNPs catalyst can be easily recovered using
an external magnet; and
In order to investigate the effect of substituent groups, the
Heck arylation of a variety of aryl iodides, aryl bromides
and aryl chlorides with various vinylic substrates was
examined and different products were obtained in good to
excellent yields. Table 2 clearly reveals that the ImmPd(0)‐
MNPs catalyst is effective for the Heck reaction.
As clearly evident from Table 2, the cross‐coupling
reaction of iodobenzene derivatives is responsive to both
electron‐rich and electron‐poor substituents and the reaction
gives the corresponding products in excellent yields
(Table 2, entries 1–6). The Heck reaction of both electron‐rich
and electron‐deficient aryl bromides also proceeds efficiently
to provide the desired products with excellent yields (Table 2,
entries 7–12). Moderate yields of products are obtained using
aryl chlorides in the presence of the ImmPd(0)‐MNPs catalyst
and also the temperature for the Heck coupling of aryl
chlorides is 80°C under reflux conditions (Table 2, entries
13 and 14). It should also be noted that aryl bromides can
• the reactions proceed at room temperature for both aryl
iodides and aryl bromides.
2.4 | Recycling of ImmPd(0)‐MNPs catalyst for heck
reaction
The level of reusability is one of the significant factors for
heterogeneous catalysts. To examine the reusability of the
catalyst, the reaction of 4‐iodotoluene with methyl acrylate
under optimized reaction conditions was used. When the
reaction was completed, the catalyst was separated using an
external magnet, washed with water and acetone (3 × 5 ml)
and dried at room temperature to be used in the next run.
The recycled catalyst could be reused eight times and no
significant decrease was observed in its activity (Figure 8).
This is also quantitatively supported by ICP analysis. ICP
analysis after eight cycles of recycling of the catalyst shows
that only a small amount of palladium metal is removed from
the Fe3O4–CS–methionine support. In order to determine
whether the observed catalytic activity is from the supported
palladium nanoparticles on the Fe3O4–CS–methionine and
not from leached palladium in solution, we performed the
reaction of 4‐iodotoluene with methyl acrylate under the opti-
mized reaction condition. After completion of the reaction,
the catalyst was removed using an external magnet and the
obtained aqueous solution from the extraction was applied
TABLE 2 ImmPd(0)‐MNPs‐catalyzed Heck reaction between various aryl
halides and olefins
Entry
R
X
Y
Time (h)
Yield (%)a
1
4‐Me
I
I
CO2Me
CO2Bu
CO2Bu
Ph
1.5
2
96
89
93
90
90
86
90
83
61
85
93
80
73
67
2
4‐Me
4‐OMe
4‐OMe
H
3
I
1.5
2.25
2
4
I
5
I
CO2Bu
CO2Bu
CO2Bu
Ph
6
4‐CN
4‐OMe
4‐OMe
4‐CH3CO
H
I
4.5
6
7
Br
Br
Br
Br
Br
Br
Cl
Cl
8
8.75
10
6.25
5
9
CO2Me
CO2Bu
CO2Me
Ph
10
11
12
13b
14b
4‐Cl
4‐NO2
H
8
CO2Bu
Ph
5.5
6
4‐NO2
aIsolated yield.
bReaction conditions: aryl halide (0.5 mmol), olefin (0.6 mmol), K2CO3 (1 mmol),
TBAB (0.25 mmol), catalyst (0.02 g, 0.28 mol%) and H2O (2 ml) under reflux.
FIGURE 8 Catalyst reusability test of the ImmPd(0)‐MNPs catalyst

6
HAJIPOUR AND TAVANGAR‐RIZI
for the next reaction between 4‐iodotoluene with methyl
acrylate under optimized conditions. After a similar purifica-
tion process, the isolated yield of products was less than 8%.
ICP analysis of the aqueous solution obtained from extraction
shows that only 0.3 ppm of palladium is in this solution.
TEM images were obtained and ICP analysis was conducted
of the recovered catalyst to study the possible changes in
palladium particle morphology/size and palladium content
on the catalyst surface in comparison with fresh catalyst. As
shown in Figure 1(b), the TEM image of the catalyst indicates
that the morphology and size of the catalyst are negligibly
changed after eight times of recycling. Furthermore, the
ICP analysis data for the reused catalyst after recycling eight
times demonstrate that during the reaction process only a
small amount of palladium nanoparticles (0.3 ppm) is lost.
These results verify that the high catalytic activity is related
to the ImmPd(0)‐MNPs catalyst and not to leached palladium.
Column chromatography was carried out on columns of silica
gel 60 (70–230 mesh).
4.2 | Catalyst preparation
4.2.1
| Preparation of CS–methionine
Methyl methioninate (10 mmol, 1.28 g) was added to a flask
containing chitosan (1 g) in DMF (40 ml). The resulting
mixture was refluxed for three days under nitrogen
atmosphere. The product was allowed to cool to room
temperature followed by separation to afford the methionine‐
functionalized chitosan. Then, the product was collected and
washed with methanol several times to remove the impurities
and dried.
4.2.2
| Preparation of Fe3O4–CS–methionine
Fe3O4 nanoparticles were prepared without using any
plugging agent or surfactant via conventional co‐precipitation
of iron(II) sulfate and iron(III) chloride according to a
reported procedure.[34] After sonication, Fe3O4 nanoparticles
(2.1 g) were treated with CS–methionine (0.7 g) in 2 wt%
acetic acid solution. The resulting mixture was sonicated for
20 min and then stirred for 30 min at room temperature. The
product was collected and washed with ethanol and deionized
water several times. After drying in a vacuum oven at 70°C
overnight, the Fe3O4–CS–methionine support was obtained
as a dark solid.
3
| CONCLUSIONS
In summary, we have demonstrated the preparation, charac-
terization and application of a new and high‐performance
catalyst system for the coupling of aryl iodides and bromides
with olefins in a green environment. The yields for the alkene
derivatives, with respect to reaction time, show that the
catalyst has excellent activity. Moreover, the ImmPd(0)‐
MNPs catalyst is very stable and can be recovered easily using
an external magnet without loss of activity. We believe that
this catalyst provides great potential for further convenient
applications in other palladium transformations in the future.
4.2.3
| Preparation of ImmPd(0)‐MNPs
To a mixture of magnetic Fe3O4–CS–methionine (0.5 g) in
ethanol (20 ml) was added Pd(OAc)2 (0.05 g) and stirred
for three days at room temperature. Then, the powder was
filtered and washed with acetone several times. The ImmPd
(0)‐MNPs catalyst was obtained as a black powder.
4
| EXPERIMENTAL
4.3 | General procedure for heck reaction in presence
of ImmPd(0)‐MNPs catalyst
4.1 | Chemicals, instrumentation and analysis
All chemical reagents were purchased from Merck and
Aldrich and were used without further purification. Chitosan
was purchased from Acros Organics and its molecular weight
In a typical experiment, to a flask containing a mixture of aryl
halide (0.5 mmol), olefin (0.6 mmol), TBAB (0.5 equiv.) and
K2CO3 (1 mmol) in 2 ml of water, ImmPd(0)‐MNPs catalyst
(0.015 g, 0.21 mol%) was added and stirred in room temper-
ature for the time specified in Table 2. The reaction was
monitored by TLC or GC. After consumption of aryl halide,
the mixture was cooled to room temperature and filtered. The
remaining solid was washed with water and acetone
(3 × 5 ml) in order to separate the catalyst. After the extrac-
tion of the reaction mixture with ethyl acetate (3 × 5 ml),
the organic extract was dried over CaCl2. The products were
purified by column chromatography (n‐hexane–ethyl acetate)
to achieve the desired purity.
1
was 1 × 105–3 × 105 g mol−1. H NMR and 13C NMR
spectra were recorded with a Bruker (250 and 62.9 MHz)
Avance DRX in pure CDCl3 solvent with tetramethylsilane
as internal standard. FT‐IR spectra were obtained as KBr
pellets with a JASCO 680 Plus spectrophotometer for
characterization of the ImmPd(0)‐MNPs catalyst. Magnetic
measurement was done with a vibrating sample magnetome-
ter at 0.0001–50 emu. TEM (Zeiss‐EM10C, 80 kV) and FE‐
SEM (MIRA3 TESCAN) were used to characterize the
ImmPd‐MNPs catalyst. TGA of the catalyst was conducted
using a lab‐made TGA instrument. XRD (D8, Advance,
Bruker) was used for characterization of the ImmPd(0)‐
MNPs catalyst. Reaction monitoring was accomplished using
TLC or GC (BEIFIN 3420 gas chromatograph equipped with
a Varian CP SIL 5CB column: 30 m, 0.32 mm, 0.25 mm).
ACKNOWLEDGMENTS
We gratefully acknowledge the funding support received for
this project from the Isfahan University of Technology

HAJIPOUR AND TAVANGAR‐RIZI
7
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How to cite this article: Hajipour, A. R., and
Tavangar‐Rizi, Z. (2016), Methionine‐functionalized
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ble catalyst for Heck reaction of aryl iodides and aryl
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